The present invention relates to lock and key, and more particularly to a lock assembly comprising a lock cylinder, having a multiple locking permutations, associated with a key to provide more locking permutations and combinations so as to ensure the security function of the lock assembly.
The conventional lock and key assembly, such as barrel lock, utilizes specific engagement or disengagement between a plurality of pin-tumblers in the locking cylinder and the key""s serrations correspondingly to control the locking and unlocking functions thereof.
Virtually, all mechanical locking devices are subject to tempering, possibly resulting from loss of keys, duplication of keys, and picking due to its limited mechanical structure and theory. Thus, one of the major drawbacks of the conventional locking assembly is that the pin-tumblers of such conventional lock assembly can be seen through the lock cylinder such that the pin-tumblers can respectively be pressed in order to unlock the lock assembly. In addition, the easiest way to unlock the lock assembly is to destroy all the pin-tumblers of the lock assembly. Therefore, the see-though lock cylinder of the lock assembly cannot ensure the security function thereof.
Moreover, the serrations of the key may be repeatedly duplicated such that the key can open several locks by fully inserting the key into the lock cylinder or just half way of the lock cylinder to match the pin-tumblers thereof.
For security purpose, an electronic lock assembly having a predetermined cipher preset therein is provided recently. However, the electronic lock assembly is too expensive to install since it must be incorporated with a computer such that the electronic lock assembly cannot be popular in used. Thus, the electronic lock assembly can be easily unlocked by someone hacks in the computer or by decoding the cipher.
A main object of the present invention is to provide a lock assembly which comprises a lock cylinder associated with a key, wherein the lock cylinder comprises at least two lock rotors having different locking permutations in such a manner that the key must fit to unlock the lock rotors in order to unlock the lock assembly. Therefore, the lock assembly can provide more locking permutations and combinations so as to ensure the security function of the lock assembly.
Another object of the present invention is to provide a lock assembly, wherein the lock cylinder further comprises a protective rotor coaxially positioned in front of the lock rotor such that the tumblers of the lock rotor cannot be seen through the opening of the lock cylinder, so as to further ensure the security function of the lock assembly. Therefore, the present invention can prevent the lock assembly from being intentionally unlocked by any tools through a keyway thereof.
Another object of the present invention is to provide a lock assembly which avoids the drawbacks of easy picking and key duplicating of the conventional mechanical lock and key assembly by eliminating the serrations of the keys to associate with the mechanical lock cylinder by fitting into the keyway thereof.
Another object of the present invention is to provide a lock assembly, wherein in order to unlock the lock assembly, the serrations of the key must match both the lock rotors for disengaging the tumblers thereof with respect to the lock cylinder. Therefore, even though the serrations of the key match the first lock rotor, the lock assembly cannot be opened without matching another lock rotor.
Another object of the present invention is to provide a lock assembly, wherein the arrangement of the tumblers, which is not limited to one or two opposing rows as in the mechanical lock and key assembly, can include any possible number of tumblers aligned around anywhere of the entire cylindrical surfaces of the key and keyways correspondingly, so that the present invention can provide more locking permutations and combinations to ensure the security function of the lock assembly.
Accordingly, in order to accomplish the above objects, the present invention provides a lock assembly, comprising:
a lock cylinder for actuating a latch assembly wherein the lock cylinder comprises:
a lock sleeve having an axial rotor hole and a plurality of first and second tumbler sockets radially distributed on an inner surface of the lock sleeve;
a plurality of tumblers being coaxially placed in the first and second tumbler sockets respectively;
a lock rotor assembly, comprising:
a first lock rotor, having a tubular shaped, being rotatably and coaxially fitted in the axial rotor hole of the lock sleeve to define a first keyway therethrough, the first lock rotor having a plurality of first locking holes radially distributed on an outer circumferential surface of the first lock rotor, wherein each of the first locking holes is capable of coaxially aligning with the first tumbler sockets respectively;
a second lock rotor, having a tubular shaped, being rotatably and coaxially fitted in the axial rotor hole of the lock sleeve to define a second keyway therethrough wherein the second keyway is normally misaligned with the first keyway, the second lock rotor having a plurality of second locking holes radially distributed on an outer circumferential surface of the second lock rotor, wherein each of the first locking holes is capable of coaxially aligning with the second tumbler sockets respectively; and
a plurality of lock pins being coaxially placed in the first and second locking holes respectively; and
a plurality of resilient elements being coaxially disposed in the first and second tumbler sockets respectively for applying urging pressures on the tumblers to move inwardly towards the first and second locking holes until an inner portion of each of the tumblers is disposed in the respective first and second locking hole and an outer portion of the tumbler is disposed in the respective first and second tumbler socket so as to lock up the rotational movements of the first and second lock rotors within the lock sleeve; and
a key comprising a key head having predetermined locking serrations arranged in such a manner that when the key head is inserted into the first keyway, the locking serrations of the key head are adapted to drive the lock pins to pull the tumblers moving outwardly into the first tumbler sockets correspondingly to unlock the first lock rotor and enable the first lock rotor freely rotating until the first keyway is aligned with the second keyway, simultaneously, the key head being adapted to insert into the second keyway such that the locking serrations of the key head are adapted to drive the lock pins to pull the tumblers moving outwardly into the second tumbler sockets correspondingly so as to unlock the second lock rotor to enable the second lock rotor to freely rotate to control the locking and unlocking of the latch assembly.